Spring MVC support

AcrossWebModule activates support for WebMvcConfigurer beans in other modules.
Any WebMvcConfigurer(often an extension of WebMvcConfigurerAdapter) will be detected and used to configure the mvc support.
Note that WebMvcConfigurer beans do not need to be exposed.

AcrossWebModule and ConversionService

AcrossWebModule requires a FormattingConversionService bean named mvcConversionService to be present.
If there is none, one will be created and exposed. By default the parent conversionService bean will be reused if
it implements the right interface. If you want to manage the mvcConversionService separately, simply create
a FormattingConversionService with the right name in the parent context.

The mvcConversionService will be passed to all WebMvcConfigurer instances in order to add formatters. It is also
the default ConversionService attached to the WebDataBinder.

There will be at least 2 ConversionService beans in the across context when AcrossWebModule is enabled:
conversionService and mvcConversionService. If you have duplicate bean exceptions due to unqualified autowiring,
you should make one of both primary.